Leak detecting apparatus



Oct. 22, 1935. D. 'E. DASHER LEAK DETECTING APPARATUS Filed May 29, 19313 NVENTOR 1 ATTORNEYS Patented Oct. 22, 1935 UNITED STATES FFECE LEAKDETECTENG APPARATUS Application May 29, 1931, Serial No. 541,094

2 Claims. (Cl. 23-253) My invention relates to leak detecting apparatus.It is especially concerned with apparatus for testing for leakage in arefrigerating system employing halogen derivatives and particularlyhalo-fiuoro derivatives of hydrocarbons as refrigerants.

In refrigerating apparatus, refrigeration is produced by the evaporationof a volatile liquid, the .vapors being compressed and liquefied andagain permitted to evaporate within an evaporator, thus producing eithercontinuous or intermittent refrigeration as may be desired. It will beappreciated that it is essential for refrigerating apparatus to be quitefree from leaks, even minute ones. Otherwise either the refrigerant willgradually escape or else air will gradually leak into the apparatus. Ineither event, the apparatus will gradually produce less and lessrefrigerating elfect, although it is apparently working perfectly inevery other respect. Consequently, it is desirable to thoroughly subjectthe apparatus to tests which will show the existence of the smallestleak before such apparatus is installed and occasionally after theinstallation of such apparatus. It will also be appreciated that suchtests must be of a simple nature for use in the field and inexpensive toperform, particularly where the apparatus is manufactured under quantityproduction.

The objects of my invention are to provide an improved apparatus fordetecting leaks in a closed system, such as a refrigerating systememploying a halogen derivative as the refrigerant and more particularlyto provide leak detecting.

apparatus wherein the halogen content of the refrigerant is caused toreact with an incandescent metal to form a volatilized metallic halidecapable of emitting a characteristic color.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing, wherein a preferred form' of the present invention is clearlyshown.

In the drawing:

Fig. 1 is a. sectional view of one form of apparatus;

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1; and

Fig. 3 is a view in section of a modified form of apparatus.

In Figs. 1 and 2 there is disclosed one form of leak detecting apparatusembodying features of my invention. It consists essentially of a burnerhaving supported in the flame produced thereby a metal, such as copper,and having means for conducting to the heated copper any halogenderivative that may be escaping from the apparatus to be tested.

More specifically, it comprises a base standard indicated at iii havingintegral legs 1!, and 5 provided with a central upstanding hollowed outportion i2 forming a well 53 in the base standard it. A passage 44communicates at one end with re well 53, and has its other end enlargedas shown at it to receive the threaded end of the 10 nipple iii, theother end of the nipple it being corrugated to receive one end of theflexible exploring tube ii. A second passage 26 has one endcommunicating with the well 13, and has its other end enlarged as shownat 22 to receive the 15 ireaded end of a second nipple the other end ofthe second nipple 2d being likewise corrugated to receive a compressedair tube, not shown on the drawing.

Extending upwardly through the base portion 20 it and threadedthereintois an upstanding tube 23 provided with a longitudinallyextending passage 29 therein. At the lower end of the passage 29 thereis formed in the tubular member annular chamber 33 communicating withone 25 end of a passage 3!. The other end of the passage EE is enlargedas shown at 32. to receive the threaded end of a third nipple 34, theouter end of the third nipple being likewise corrugated to receive aflexible gas line, not shown 30 on the drawing. 3

Threaded into the upwardly extending portion 82 and locked in positionby the lock nut 31, is a tubular member 36 having threaded to its upperend a burner 33 provided with a plurality 35 of openings as shown at 39.A metallic member, herein shown as a copper cone 4!, is carried by a rod$3 screw threaded into the burner 38, so as to be carried in the flameproduced at the burner. Within and carried by the tubular 40 member 39is a block it provided with the longitu-dinally extending passage 46.The passage 46 is restricted at one end as shown at 48 and flaresoutwardly and upwardly as indicated at 50. The restricted end 33 of thelongitudinally extending 45 passage is positioned directly above the endof the tubular member 28 and forms in efifect a venturl. Thisarrangement is often called a jet pump.

In the operation of the device disclosed in Figs. 50 1 and 2, naturalgas or any other suitable fuel, passing through the nipple 34, passage3!, the passage as in the tubular member 28, and the passage #6, is fedto the burner 33. Compressed air, passing through the nipple 24, thepassage 05 pass with air through the tube H.

H by the action of the compressed air and natural gas passing throughthe venturi. Any halogen derivative leaking from the apparatus willComing in contact with the incandescent metal 4! the halogen derivativewill break down forming free halogen which will react with the coppercone 41 to form a volatilized copper halide. opper halide whenvolatilized will emit a bluish-green color,

7 thus indicating a leak.

In Fig. 3 I have shown amodiiied form of apparatus. The structurecomprising the tubular member 36, carrying the block 44', the burner38', and cone 4!, is identical with the structure indicated by likereference characters minus the primes in Figs. 1 and 2. This embodimentdifiers from that disclosed in Figs. 1 and 2 only in the structure ofthe base portion. In this modification, the base portion consists of avertically extending block 50 enlarged at its upper end 6| to form thewell 62. The tubular member 36' is threaded into the enlarged portion 51and communicates with the well 52. A look nut 3'! looks the tubularmember 36' in position. At its lower end the block 50 is in the form ofa narrow elongated member .64 provided with a passage 85.

The upper end of the passage is enlarged to receive the threaded end ofa tube 28', which tube 28' has a passage 29' forming a continuation ofpassage 65. The tube 28' extends upwardly into the tubular member 35 toa point just below the block 44. At its lower end, passage 55 isenlarged to receive the threaded end of the nipple 34, the other end ofthe nipple 34 being corrugated to receive a gas tube, not shown.

Two conduits, it and 213', corresponding to the passages I4 and 26 shownon Fig. 1, communicate with the well 62, and extend downwardly along theelongated portion 55 to communicate with a conduit I 'i' and acompressed air line respectively. A skirt depending from the enlargedportion ti surrounds the conduits l4 and 20'.

The device disclosed in Fig. 3 operates in substantially the same way asthe apparatus disclosed in Figs. 1 and 2. Natural gas, passing throughthe passage 55, the passage 29', and

through the opening in the block 44, is fed to 5 the burner 38'.Compressed air passing through the conduit 25, the well 62, is likewiseconducted to the burner 38. The passage of the natural gas and thecompressed air through the venturi formed by the block 44 draws inwardlythrough 10 the exploring tube l4 air from the vicinity of the apparatusto be tested. Any halogen derivative contained in the air in theimmediate vicinity of the apparatus to be tested will pass with the airthrough the tube N and, coming in con- 15 tact with the incandescentcopper 41', will break down. The free halogen formed will react with theheated copper to form a. volatile metallic halide, which compound willemit a characteristic bluish-green color. 7 a

While the form of embodiment of the invention as herein disclosed,constitutes a preferred form it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow. 25

What is claimed is as follows:

1. Apparatus for detecting leaks in a closed system containing a halogenderivative comprising a burner having venturi means for drawing in airfrom the vicinity of said closed system to 30 be tested, a flexibleexploring tube connected to the venturi means for conducting the air tobe tested,'means for conducting fuel to said venturi means to provide aflame, and a metal capable of reacting with free halogen and coloringthe 35 flame, said metal being supporting within the flame by theapparatus.

2. Apparatus for detecting leaks in a closed system containing a halogenderivative comprising a burnena mixing means connected to the 40 burner,means for conducting fuel to said mixing, means for providing a flame atthe burner, said mixing means including an air sucking means for drawingin air, a flexible exploring tube extending from the air sucking meansto the vicinity 01 5 the closed system to be tested for rapidlyconducting the air frcm the point suspected of leakage to the burner,and a metal capable of reacting with a free halogen and coloring theflame, said metal being supported within the flame. 50

DON E. DASHER.

